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Cactus.man CC BY-SA 4.0 Wikimedia Commons

Flathead Lake

Lake

Flathead Lake in Montana is a wide, clear freshwater basin near Polson and Bigfork. Summer visitors fish, sail and camp along state parks, and orchards around the southern shore sell cherries.

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In this guide

Flathead Lake essentials

Address: Flathead Lake, Polson / Bigfork area, Montana, USA (region rather than single address)
Website: f flatheadlake.org
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About Flathead Lake

Flathead Lake is a large natural freshwater lake in northwest Montana, United States, and is one of the region’s principal inland water bodies. The lake is regionally important for recreation, fisheries and scenic value.

The lake and surrounding lands have long been used by Indigenous peoples and later by settlers for fishing, transport and agriculture; modern recreational development expanded through the 20th century with growth in tourism infrastructure. Management has combined recreation, conservation and water-use considerations.

Located in northwest Montana, Flathead Lake lies south of the city of Kalispell and north of the Mission Mountains region, within Flathead County and nearby counties; towns such as Polson sit on its shores and serve as local access points.

  • Regional significance: Recognized as the largest natural freshwater lake in the western contiguous United States, it is a major regional recreation resource for boating, fishing and tourism.
When to Go

Best Time to Visit Flathead Lake

Summer is prime for water activities; late spring and early autumn are preferable for quieter visits and wildlife watching.

Summer
June-August · 12-28°C
Warmest, best for boating, swimming and lakeside recreation; busiest period.
Late Spring
May-June · 5-18°C
Cooler water but good time for birding and fewer crowds.
Early Autumn
September-October · 5-20°C
Crisp air and colorful foliage around the lake shores; quieter marinas.

Weather & Climate near Flathead Lake

Climate

Flathead Lake's climate is classified as Warm-Summer Continental - Warm-Summer Continental climate with mild summers (peaking in August) and freezing winters (coldest in January). Temperatures range from -4°C to 26°C. Moderate rainfall (505 mm/year).

Air Quality: AQI 29 Good
Temperature & Rainfall
Temperature Range
26°
Warmest Month
-4°
Coldest Month
Monthly Conditions
Month Comfort Temp Feels Rain Sky Humidity Wind UV Daylight
January - -4° - 1° -5° 44 mm - - 2.8 m/s - -
February - -3° - 3° -4° 30 mm - - 2.9 m/s - -
March - -2° - 6° -1° 33 mm - - 3.2 m/s - -
April - 0° - 11° 3° 33 mm - - 3.4 m/s - -
May - 4° - 16° 10° 63 mm - - 3.3 m/s - -
June - 8° - 21° 14° 65 mm - - 3.2 m/s - -
July - 11° - 25° 18° 35 mm - - 2.9 m/s - -
August - 11° - 26° 18° 42 mm - - 2.8 m/s - -
September - 7° - 20° 14° 42 mm - - 2.7 m/s - -
October - 3° - 14° 7° 31 mm - - 2.8 m/s - -
November - 0° - 6° 1° 39 mm - - 2.9 m/s - -
December - -2° - 3° -3° 48 mm - - 2.8 m/s - -
Getting There & Around

How to Get to Flathead Lake

Flathead Lake is accessible by car from Kalispell (about 30-45 minutes north) via US-93 to Polson on the southern shore. Regional flights to Glacier Park International Airport (FCA) in Kalispell provide the nearest air access; car rental recommended.

Tips for Visiting Flathead Lake

  • Renting a car or boat is the best way to explore the lake's many public access points and lakeside towns
  • Visit Flathead Lake during late spring or early autumn for fewer tourists and pleasant water temperatures
  • Try local huckleberry pie - a regional specialty often sold at roadside stands